Overheat warning assembly



Aug. 14, 1962 J. M. WALLACE 3,049,580 OVERHEAT WARNING ASSEMBLY Filed April 20. 1959 JOSEPH M. PW/1L a 2:5,

INVENTOR.

BY M

[frag/V53.

Patented Aug. 14, 1962 3,0495% OVERHEAT WARNKNG ASSEMBLY Eoseph M. Wallace, Los Angeles, Calif. (5617 Corryne Place, Culver City, Calif.) Filed Apr. 20, 1959, Sell. N0. semen 8 (llaims. (Cl. W t-59) This application relates to terminal mounting arrangements.

An object of the invention is to provide an over-heat warning assembly, particularly one suitable for use on aircraft.

Another object of the invention is to provide an insulator for supporting a thermostat and terminals therefor in conjunction with fire walls for mounting thermostats in the fire wall exposed to heat on one side to be protected, with electrical connections on the opposite side and electrically isolated from the protected side.

Another object of the invention is to provide a compact terminal assembly of simple construction, very reliable, of light weight and accomplishing great saving in weight and space as well as cost, for rendering it very useful for utilization on aircraft.

Other and further objects, features and advantages of the invention will become apparent as the description proceeds.

In carrying out the invention in accordance with a preferred form thereof, a hollow insulater housing is employed, having a flanged base which is open, which may be bolted around the edges of an opening in a fire wall and into which a thermostat unit may be inserted. At the opposite end from the open base there is a transverse enclosure wall with square openings, separated by a projecting portion. Square cross-sectioned terminals are mounted in the square openings so as to fit therein. Solder globules on the terminals outside the enclosure wall prevent the terminals from dropping into the interior and, likewise, soldered conductors extending transversely through the lower ends of the terminals, lock the terminals in place to prevent them from being pulled out of the transverse enclosure wall.

, A better understanding of the invention will be afforded by the following detailed description considered in con junction with the accompanying drawing, in which:

FIG. 1 is a view in perspective of an embodiment of the invention,

FIG. 2 is a plan View of the apparatus of FIG. 1,

FIG. 3 is a view of a longitudinal section represented as cut by vertical plane through the center of the device of FIGS. 1 and 2,

FIG. 4 is a detail view illustrating the manner in which the terminal blocks are locked in the square openings, and

FIG. 5 is a bottom plan view of the device.

Like reference characters are utilized throughout the drawings to designate like parts.

Referring now in greater detail to the drawings, the illustrated embod ment comprises a hollow insulator housing 11 having a flanged base 12. The housing 11 is circular in cross-section as shown, with a hollow interior opening at the bottom toward the base to form a cylindrical cavity 13. The lower portion 14 of the cavity 13 is adapted to receive the casing of a thermostat unit 15, which does not in itself constitute my present invention, being of conventional type provided with terminal lugs 16 and 17 which extend into the interior 13 of the insulator housing 11 as it is utilized for mounting the thermostat unit 15. For retaining thermostat unit in place, an overhang or lip 18 is provided on the lower edge of the opening 14 to receive a snap-type retaining ring 19 hearing against the edges of the lower surface 21 of the thermostat unit 15.

At the top, or the end of the housing 11 away from 2 the base 12, a transverse closure wall 22 is provided. The transverse closure wall 22 has a pair of non-circular, such as square openings 23 and 24, e.g., with outer edges 25 preferably beveled, as shown.

Terminals 26 and 27 of brass or other suitable, highlyconducting metal are provided which have square crosssections, fitting relatively closely in the square openings 23 and 24. The square openings 23 and 24 are at the outer portions of the transverse wall 22 so that the terminals 2'6 and 27 extend downward along the irmer surfaces of the cavity 13 so as to accomplish a high degree of compactness and permit a housing 11 of the minimum diameter to be employed. The fact that the openings 23 and 24, and the terminals 26 and 27 are not circular avoids turning effect from a screw driver. Moreover, having flat sides for the terminals gives maximum compactness for a given current-carrying capacity. Preferably, there is an upwardly projecting portion 28 for physically separating the space occupied by the terminals 26 and 27, so as to guard against possible short-circuiting by bridging of the terminals in the event of electrically conducting particles falling upon the unit.

As better shown in FIGS. 1 and 2, the projecting portion 28 has lateral surfaces 29 shaped as portions of cylinders substantially concentric with the terminals 26 and 27, so that terminal screws with heads 31 and 32 slotted to receive a screw driver, may be tightened or loosened by a conventional screw driver without danger of shortcircuiting against the other screw and without impairing the maximum degree of insulation protection, as well as providing insulator strength.

As shown, the terminals 26 and 27 have threaded bores 33 for receiving the terminal screws. The screw heads 31 and 32 are of greater diameter than the transverse dimension or width of the square cross section terminals 26 and 27, so that there is no danger during assembly or making connections that the terminals 26 and 27 will fall through the square openings 23 and 24.

The lower ends of the terminals 26 and 27 are provided with transverse openings 34 and 35 respectively, quite close to the lower surface 36 of the transverse wall 22. Leads or conductors 37 are provided for connecting the terminal lugs 16 and 17 of the thermostat 15 to the terminals 26 and 27 respectively. It will be understood that the ends of the leads 37 are bare, the lower ends being soldered or crimped to the lugs 16 and 17, which are preferably surrounded by insulating sleeves 38. The bared upper ends 39 of the leads or conductors 37 extend through the transverse openings 34 and 35 and are either looped over or pushed through and soldered at the end 41, as shown in FIG. 4, solder being preferably provided in any event for making good electrical connections.

As shown more clearly in FIG. 4, the portions 41 and 42 of the conductor ends 39, even though sharply bent, form abutments which prevent the terminals 26 and 27 from being pulled upward through the openings 23' and 24 and thereby lock them in place. It will be understood that if desired the leads 37 may be soldered to the thermostat lugs 16 and 17 before assembly and that the upper ends 39 may be inserted in the terminals and soldered thereto before the terminal screws 31 and 32 are inserted in order to enable the soldering operation to be carried on conveniently, after which the assembly is pushed into the interior 13 of the housing 11, the snap ring 19 is applied and the terminal screws 31 and 32 are threaded in place. This operation may be carried out with the housing 11 inverted. Thereafter, with the housing placed on the work table with the base 12 down, the oversize terminal screw heads 31 and 32 prevent the terminals from falling through the square transverse Wall holes while the further operations are conducted.

Preferably, in order to hold the terminals 26 and 27 (3 relatively immovable in a fixed position, solder globules 43 are applied to the outer surfaces of the terminals 26 and 27 where the insulator wall is beveled, as shown at 25, providing recesses for the solder globules 43.

The housing 11 may be composed of any suitable insulating material such as ceramic or fiberglass impregnated with insulating plastic, such as phenolic plastic or polytetrafluorethylene, for example.

When the over-heat warning assembly so formed is utilized on aircraft having parts enclosed by fiberglass sheeting, an opening just suflicient to receive the circular portion of the insulator housing 11, may be cut in the fiberglass sheeting. The over-heat warning assembly may then be inserted through such fiberglass sheeting 44 represented in dashed lines in FIG. 3 and secured thereto by screws 45 or the like extending through openings 46 in the base 12.

The assembly is so inserted in the fiberglass sheeting or fire wall 44 that the thermostat surface 21 is on the side of the sheeting 44 which is to be protected by observation of temperature and the electrical connections such as by conductors 47 from the terminals 26 and 27 are made on the opposite side of the Walls so as to avoid any explosion hazard or electrical hazard on the side of the sheeting 44 to which the thermostat surface 21 is exposed.

While the invention has been described as embodied in concrete form and as operating in a specific manner in accordance with the provisions of the patent statutes, it should be understood that the invention is not limited thereto, since various modifications will suggest themselves to those skilled in the art without departing from the spirit of the invention, the scope of which is set forth in the annexed claims.

What is claimed is:

1. An over-heat warning assembly comprising in combination a hollow, insulating plastic-impregnated fiberglass housing, a thermostat having a pair of connecting lugs, said housing having a base open to the interior of the housing with said thermostat mounted in, said base and projecting into the housing interior with the connecting lugs in said housing interior, the housing having a transverse enclosure wall across the top of the hollow interior, with square openings therein on either side, and an upwardly projecting portion between and partially surrounding said square openings, square terminals in said square openings substantially filling said openings and projecting through the top closure wall, said terminals each having a lower end with a transverse opening therein, and an upper end with a threaded, terminal screwreceiving bore, conductors, each having an end extending through one of said transverse terminal openings to lock the terminal in its square housing opening, and a lower end electrically connected to one of the thermostat lugs for electrically connecting the terminal to the thermostat, and each terminal having a solder globule on the side thereof above the housing closure wall for holding the terminal in the transverse closure wall of the housing, terminal screws being provided which are threaded in said terminals and have circular heads of diameter exceeding the terminal thickness for preventing the terminal from falling into the housing interior prior to application of the solder globule.

2. In combination a hollow, insulating plasticimpregnated fiberglass housing and a pair of square terminals mounted in said housing, the housing having a base open to the interior of the housing for receiving an electrical device to be connected by the terminals, the housing having a transverse enclosure wall across the top of the hollow interior with square openings therein on opposite sides and an upwardly projecting portion between and partially surrounding said square openings, the said square terminals substantially filling said square openings and projecting through the top closure wall, said terminals each having a lower end with a transverse opening therein, and an upper end with a threaded, terminal screw-receiv- 6:. ing bore, conductors, each having an end extending through one of said transverse terminal openings to lock the terminals in its square housing opening, each terminal having a solder globule on the side thereof above the housing closure wall for holding the terminal in the transverse closure wall of the housing, terminal screws being provided which are threaded in said terminals and have circular heads of diameter exceeding the terminal thickness for preventing the terminal from falling into the housing interior prior to application of the solder globule.

3. A compact terminal mounting block comprising in combination a hollow insulator housing having a base open to the interior of the housing for receiving an electrical device to be connected by terminals, the housing having a transverse enclosure wall across the top of the hollow interior with square openings therein on either side, and an upwardly projecting portion between and partially surrounding said square openings, square terminals in said square openings substantially filling said square openings and projecting through the top closure wall, said terminals each having a lower end with a transverse opening therein and an upper end with a threadedterminal screw-receiving bore, and conductors each having an end extending through one of said transverse terminal openings to lock the terminal in its square housing opening, each terminal having a solder globule on the side thereof, above the housing closure wall for holding the terminal in the transverse closure wall of the housing, terminal screws being provided which are threaded in said terminals and have circular heads of diameter exceeding the terminal thickness for preventing the terminals from falling into the housing interior prior to application of the soldered globule.

4. A compact terminal mounting block comprising in combination a hollow insulator housing, a pair of square terminals mounted in said housing, the housing having a hollow interior with an opening at the bottom, the housing having a transverse enclosure Wall across the top of the hollow interior with square openings therein and the square terminals being located in said square openings substantially filling said openings and projecting through the top closure wall, said terminals each having a lower end with a transverse opening therein and an upper end carrying means increasing the dimension of the terminal for holding the terminal in the transverse closure wall of the housing, and a conductor for each of said terminals, each having an end extending through one of said transverse terminal openings to lock the terminal in its square housing opening.

5. A compact terminal mounting block comprising in combination a hollow insulator housing, a terminal mounted in said housing, the housing having a base open to the interior of the housing for receiving an electrical device to be connected by the terminal, the housing having a transverse enclosure wall across the top of the hollow interior with an opening therein, the terminal substantially filling said wall opening and projecting through the top closure wall, said terminal having a lower end with a transverse opening therein and an upper end, a conductor having an end extending through said transverse terminal opening to lock the terminal in its housing opening, the terminal having a solder globule on the side thereof above the housing closure wall for holding the terminal in the transverse closure. wall of the housing.

6. A compact terminal mounting block comprising in combination an insulator housing, a pair of square terminals mounted in said housing, the housing having a hollow interior with an access opening, the housing having a transverse Wall across the block forming a closure for the hollow interior with square openings therein and the square terminals being located in said square openings substantially filling said openings and projecting through the transverse closure wall, said terminals each having an inner end with a lateral opening, therein and an outer end with a threaded coaxial bore therein, terminal screws each in one of said threaded bores, each having a head of greater diameter than the transverse dimension of the terminal for holding the terminal in the transverse closure wall of the housing, and means extending into each of said lateral terminal openings to lock the terminal in its square housing opening.

7. A terminal assembly for locking in an insulating Wall of a predetermined thickness dimension having a square opening, said assembly comprising a square crosssection post composed of electrically conducting material and a terminal screw, the post having a threaded bore mating the terminal screw, the screw having a head of greater diameter than the width of the post, the post having a transverse opening at the lower end thereof adapted to receive a conductor end, and an abutment fused to the side of the post spaced from the end a distance corresponding to said wall thickness dimension whereby the said abutment and a conductor received in said transverse opening serve as Wall abutting, locking means preventing longitudinal movement of the post and its square cross-section serves as locking means against rotation thereof.

8. A compact terminal mounting block comprising in combination a hollow insulator housing, a terminal mounted in said housing, the housing having a base open to the interior of the housing for receiving an electrical device to be connected by the terminal, the housing having a transverse enclosure wall across the top of the hollow interior with an opening therein, the terminal substantially filling said wall opening and projecting through the top closure wall, said terminal having a lower end with a transverse opening therein and an upper end,

a conductor having an end extending through said transverse terminal opening to lock the terminal in its housing opening, the terminal having an upper end carrying means joined thereto increasing the dimension of the terminal for holding the terminal in a transverse closure wall of the housing.

References Cited in the file of this patent UNITED STATES PATENTS 672,332 Roche Apr. 16, 1901 1,786,746 Gibbs Dec. 30, 1930 1,932,456 Gaston Oct. 31, 1933 2,125,060 Barnes et a1. July 26, 1938 2,320,946 Madden June 1, 1943 2,367,449 Triplett Jan. 16, 1945 2,407,621 Weber Sept. 10, 1946 2,438,008 Hoop Mar. 16, 1948 2,649,523 Mulvany et al. Aug. 18, 1953 2,650,973 Jacobi Sept. 1, 1953 2,659,766 Fot Nov. 17, 1953 2,700,709 Byam Jan. 25, 1955 2,721,981 Modrey Oct. 25, 1955 2,751,109 Moore June 19, 1956 2,759,068 Manecke Aug. 14, 1956 2,962,691 Mande et al. Nov. 29, 1960 FOREIGN PATENTS 348,493 Great Britain May 14, 1931 172,483 Switzerland Jan. 2, 1935 127,920 Sweden Apr. 11, 1950 

